


Firefly

by Mahozahamy_Arisugawa



Category: Undertale (Video Game)
Genre: Blindfolds, M/M, Praise Kink
Language: English
Status: Completed
Published: 2019-02-27
Updated: 2019-02-27
Packaged: 2019-11-06 06:24:03
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,998
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17934491
Author URL: https://archiveofourown.org/users/Mahozahamy_Arisugawa/pseuds/Mahozahamy_Arisugawa
Summary: Red life has been as shitty as it gets, abused by his creator, broken the point were he has been forced to do things he has blocked to just keep himself alive, conditioned to believe he is worth nothing. That he didn't deserve anything good.All the good things are for other people. Not him.





	Firefly

**Author's Note:**

  * For [ChocoboFangirl (LaviniaD)](https://archiveofourown.org/users/LaviniaD/gifts).



_Gaster tall figure was standing just in front of him. Looming and terrifying. He had found out. The bastard always did. No matter how careful he was. The small blade of the scalpel in his hands trembling. A cruel and cold laugh echoed trough the walls of the laboratory._

“ _You truly believe you could kill me Sans?” a hard punch on his face hit him with enough force to send him to the floor, making him drop the blade. Then Gaster's immaculate shoe was on his spine, pressing so hard it made him whimper “Even if you do... you will never going to truly get rid of me Sans, I'm going to make your brother the worst creature you could ever imagine, I'm going to make him enjoy your suffering, I will force him to break you. Every single day of your miserable life you will beg for the pain to end”_

_Sans was crying curled in a tight ball on the floor the bruises already forming on his bones._

“ _You will remember me as long as you live Sans, no matter what you do, or where you hide... you are nothing without me. I made you, and I can end you too... you worthless piece of shit”_

_With a final kick Gaster left him alone in the darkness, Sans held his arms with his hands, shaking with the force of his whimpers. The was nothing left, just darkness, silence and the sporadic turn of the emergency lights._

_Flashing red..._

_Red..._

“red!”

Abruptly he opened his sockets, his hands fist, adrenaline running trough his body, ready to jump and fight the aggressor. Only to find the surprised face of Sans looking at him with a worried expression. Shit. He groaned internally. This was just so fucking great.

“are you okay buddy?”

“Yeah”

“are you sure? you didn't look that good, did you want a glass of water?”

“I'm fine”

“okay, okay, you good, sorry” Sans placating tone made it even worst for him.

“What is it?”

“just came by to bring you to the meeting, the three of us need to present the advances to the king Stretch is already waiting for us there”

“Okay”

He followed Sans walking mindlessly across the building. He always hated these kind of environments sterile and too bright. It made him remember _things_ that were better dead and buried. Ironically he now worked for Sans on his labs. But hey that's life for you, a meaningless never-ending pain in the ass.

Since Boss and he came here everything in his view of he world shifted upside down. Everything was totally different. A good kind of different. They weren't the only ones, Stretch and Blue also came here too, exactly at the same time, but from a different portal.

And Sans recruited Stretch and him as they both were science guys to help him establish a safe way to cross what they now called the theoretical multiverse. If two different universes touched this one, Sans concluded there have to be more.

It felt truly natural for Sans to take lead of their team. He was after all the smartest of the three. Red couldn't help but notice how passionate the guy was for science, and how dedicated he was to his work. Sans could look like Red, but he was nothing like him. He was everything Red could never be. It wasn't exactly a secret at least not to him that he liked Sans a little bit too much. But even knowing well he could never stand a chance, he was draw to Sans like a moth to the flame.

The meeting ended on a surprisingly hopeful note for the team to receive the funds they needed to keep the investigation. Now that the work hours were done and finished Sans and he were the only ones left. Sans was scribbling down a few notes, very focused and he... he was just here really.

Cleaning his space, and organizing his notes, watching the other and killing time, but deep down he was trying to find courage to talk with Sans, about anything. Hell, even work related chat could do. But nothing came to mind. Literally his mind was blank as he stared at Sans busy hands. After he finally concluded the annotations on his own notes he was ready to admit defeat and leave Sans alone, when the other closed his file abruptly and spoke to him.

“great work today red, thank you. i... want to talk with you a little more if you have the time. how about some shitty lab coffee?”

“Heh, thanks dude. Sure, who could resist some mud water?”

“well not me, i really could use some caffeine, let's go”

Sitting with their cups of coffee on an empty cafeteria, in silence was making Red very uncomfortable. The air seemed too tight, his clothes itchy. No position seem to be comfortable. He wanted to run from here, far, far away were he could feel the air blowing. Sans was silently and toying with the cup on his hands. He pressed his hold on to the mug.

“So... you wanted to talk?”

He had to break the silence. Or he was going to start screaming. He took a big gulp, to do something.

“yes, sorry... it's... i was thinking about today. your presentation was truly amazing red, i'm truly impressed, and to be honest i was just trying to find the right words to tell you i really admire your work, and well you in general... but i'm not a good conversationalist”

Red almost spit his coffee. What? Wait a fucking minute... Sans admired him?

“since you came here, since you began to work with me everything is more easy. feels like you had all the answers i was tired to search for in vain, sincerely, this investigation has gone this far thanks to you, i'm are really fortunate to have you on the team, and... sorry i'm rambling i must be really tired”

Red mind was reeling. And he was blushing a little for all the sudden compliments.

“Thanks... I really never thought my work could be...”

“sorry i didn't tell you before, sometimes i just get lost on the work, but i really appreciate all you do for me, for us. It's truly a bless to have you red, thank you so much”

“All for the science, right?”

“absolutely... red, i was thinking... if you didn't had a plan for sunday, well, maybe we could grab some grub at grillby's new place?”

“Sounds... great"

Mind blown and still blushing Red left the building taking a shortcut to home. Not believing truly his surprising strike of good luck.

 

******************

 

 

“Hey, wanna know how you call a dictionary on drugs?”

“yeah”

“high-definition”

“pffft! ha, ha, ha! you know? being an adult monster is just walking around wondering what the hell are you forgetting _”_

“Heh, heh, heh... Well I hope when I inevitably choke to death on gummy bears, they just say I was killed by bears and leave it at that”

“pffft! ha, ha, ha! I truly believe behind every angry little brother is a big brother who has absolutely no idea what he did wrong now”

“Heh, heh, heh... so fucking true. How do you call a skeleton on drugs Sans?”

“i have absolutely no idea...”

“Stretch”

“ha, ha, ha!”

For a moment, they stood there on silence, just looking at each others eyes. At first Red really nervous about today and practically gulped down his first mustard drink and asked for a second right away, feeling too sober to deal with the fact that he was with Sans, sharing a little time, besides the work. So he resorted to shitty jokes to take off a little tension. Hearing Sans laugh was amazing and addictive. He wanted to hear it more. Almost bursting in joy when Sans replied with his own jokes.

“A toast! To the bright mathematicians who thought the idea of zero, thanks for nothing!”

“ha, ha, ha!”

 

******************

The next few weekends, the two made their casual trip to Grillby's a weekly ritual now. Red had began to consider their Sundays together a thing now. Till Sans suggested they went to the movies for a change one day. And they did. The movie they both chose was an amazing work of science fiction.

Red was truly immersed on the universe of neon intergalactic battles, eating the popcorn when he felt Sans hand on his own, grabbing it so casually he almost jumped on his seat, but after the initial shock he enjoyed the warmth of Sans bones on his and an almost indiscernible blush dusted his face, after a while he even dared to hold the other's hand a little too.

After the movie ended and they began to walk home, Red missed the contact of Sans hand on his, so at risk of being a nuisance, he decided to walk more closely to him, his soul pounding on his chest. Hopefully the other would not notice it and then, after some steps of deliberation he took Sans hand.

Noticing a beautiful blue blush, spreading on Sans face, but he didn't removed the hand. So with renovated confidence and an impossibly big grin Red secured Sans hand on his own, and keep talking to the other about the movie. And how definitely they had to watch the horror one that was shown on the previews.

Sans agreed with him.

Red was amazed how well the two of their hands fit together, how easy was coordinating their steps to a comfortable pace. Not hurried, not slow. Walking while holding Sans hand felt just right. Much more sooner than what Red wished they arrived at Sans home and he found he didn't want to let the other go. But they had to, tomorrow was an important day on the investigation.

So reluctant he left his hand go, but just as the Sans was saying good night, he reached for his shoulder placing his hand there on the comfy jacket and on impulse wrapped his arm around Sans spine bringing their bodies together and Red kissed him.

******************

That was how the two of them began to date. Red just loved the way Sans always seem to know what was on his head and made him immensely happy to find Sans little thoughtful details.

Warm coffee on his office. A little greasy bag of Grillby's takeout now and then. A little mustard after work hours. Funny texts jokes of the knock knock variety. He always replied with more jokes, more on the sarcastic side, but Sans appreciate those nonetheless.

They began to hide love notes in between the other's research. Sure all the ordeal was corny and sound sappy as hell, but those little gestures made him felt wanted, loved.

Red was passing so much time on Sans house just lazying around after work, Papyrus had begun to ask him were he was the days he didn't spend the night on their couch. And Boss began to get bitchy about it too. Talking about his tardiness at chores, making a point to tell him about indecency and such. So naturally he began to bring Sans to Boss and his home.

The two of them connected on strange ways. At first Boss just scowled and grunted every time he saw Sans hanging out with Red, but with the days he actually talked to him. And thanks to that Boss found out Papyrus actually had a lot in common with him. So they both became sort of puzzle and game pals.

******************

One night as Papyrus and Boss were on a fishing trip as a male bonding friendship activity. Sans and Red had the house to themselves. And what started as a fun unwinding day away from the two tall and over energetic skeletons rapidly became an intense make out session.

Red has Sans trapped under him and was currently biting at his jaw putting to good use his sharp teeth. Just a little, teasing and nibbling at Sans neck vertebrae. Looking the slightly smaller skeleton squirm a little. Sockets shut and hands trembling. He moved his arms and pinned Sans hands over his head.

Biting a little harder as he reached Sans clavicle, licking the bone immediately after to ease the pain if any. But Sans seems lost in the waves of pleasure.

Grinning madly he slide a hand down, the other still pinning Sans wrists firmly in place. He caressed Sans iliac crest, pressing the bone beneath the overgrown pants. Touching the ilium and moving his hand closer to the sacrum in small circles. Tearing shaky breaths from Sans calling his name.

 

_Inadvertently a cold, soulless laugh echoes in his brain. An image of Gaster, looking at him as he was tied on the table. Screaming in pain... and calling for mercy._

Red shuts down. Solid in place. Still pinning Sans on the couch but he don't see him anymore.

_Everything is wrong, everything is empty, and dark. Is dangerous, his breath hurts... he couldn't stop, he is drowning. There's a cold metal drilling on his right socket... He is about to die..._

And he faints.

 

******************

Red is not normal. He had never pretended he was, and still every single little time he believes he could have something, the ever present figure of Gaster is there. Making his omen ever present. No matter how things changed, no matter he is not here, he will never truly will leave Red. Reminding him the truth.

He is nothing. He is trash. He don't stand a chance at happiness. He don't deserve anything good in life and better stop trying, unless he wants to hurt the ones he love. He need to stop before _his filth_ reaches Sans, he had to end this before he hurts Sans. Good things are for other people, not him. How could be such stupid to forget? Sans deserve someone who could make him happy. Red need to give up. Have some fucking decency and leave Sans before is too late.

And he is preparing to do so. He need to be a fucking bastard and push him now. Only Sans don't buy his bullshit. Sans fight back.

It's difficult to resist him. It's so difficult to stay away from the warmth when you have spent so much time in the cold and the darkness. Even when you now the cold is your birthplace and the darkness your home. It's unfair and cruel to be able to see the light and can't never truly feel it.

At first is terrible. He is angry at Sans, how could didn't he sees he is doing this for him. For his well being. It hurts him like hell to be apart from him, but he will do it.

Because he loves Sans.

He could give. His all. But he is not worth to receive. That is his truth. The guideline that governs his life, the one thing that is only his. He doesn't deserve. And he should be happy is the only thing Gaster truly take it from him. He is no stranger to suffer. He will stand this too. Maybe it will break him a little more, maybe the wound will bleed for years... but if it's for Sans... he will do it.

But Sans refuses to just give up. So Red does. He breaks apart and confess to Sans the truth. He can't fool him with excuses, but maybe if he told Sans the truth if he shows him the real damage on his mind, he will understand, that there is really no hope for him. No chance at redemption. The darkness in his soul is contagious, Gaster put it there himself. Making sure no one can reach him, without killing him first.

Red is afraid. This shit is really deep and he didn't want to drown again on that place, he didn't want to be there. Scared, small and defenseless once again.

As the words die on his teeth he didn't want to see Sans face, he knows he is going to find disgust and even fear those could stand what he didn't think he could see and survive is pity. Too close to care and too far at the same time.

But when he looks up, Sans is not looking at him with disgust, he isn't looking at him with pity. Sans is crying. And Red feels like shit, after all he is hurting Sans by being the shit he is.

_Worthless_ chants the voice on his mind. And he agrees.

“you are such an idiot”

The words are on point of course, but they hurt.

“how could you do this to yourself red?! why are you blaming yourself for something you have no control over? it's not your fault”

It is, Sans is just too nice to see it.

“i'm here, and i'm not moving, not without you”

It's so hard to not believe in him. Things like this don't happen to monsters like Red. Fairy tale romance is for movies and occasionally a lucky one out there. But reality, specially his is a fucking unforgiving bitch. And yet it's really hard don't held a little hope. He doesn't believe in anything. But is really hard not believe in Sans, in his words.

Red is not strong, but in Sans he had found a haven.

 

******************

And Sans stays. Even when he has seen the worst of the worst, even when he had heard the worst of his words, he still doesn't blame him. And refuses to listen when Red said is too late for him. He knows the scars run deep. Some cuts have been bleeding his entire life. He just endure it. Either them kill him or he just stop caring about the pain. Sans tell his it's not healthy, but he didn't know another way.

He stays at his house for weeks now. Waking him up for work, attempting at actually baking him some muffins and failing terrible, so bad is the damage at the kitchen Boss in person help him made something edible. Writing him small lovely notes. And Red begins to believe that maybe they could survive this.

There are more the days that the four of them have dinners together. Sometimes at Sans house some times at his. There is movie night were sometimes Alphys and Undyne from this world are invited.

And Sans began ask him to do things for him too. Sometimes they ask each other if something is needed on either house, and Red is so happy to buy groceries for him. But the thing he likes the most is when Sans asks him to read aloud to him. It's truly relaxing leave his voice filling the space of either of their living rooms. Feeling Sans bones relax on to his own body.

It's warm. It feels... familiar.

Sans keeps doing the same things he always has done before the incident. Not pretending it didn't happen or didn't exist, just not giving it any importance.

“it's just a bump red, not an abyss, please don't think so low of me, i'm not going to give up on us for this, we can handle it if you are with me”

And Red does. Because even if he feels like a fool for believing once again, he wants to, he wants to made a bridge that allows him to be with Sans, if he is not giving up, neither Red. Even when Red blames himself. Sans doesn't. Sans tell him the only reason he is doing this, is because of love.

 

******************

Still he finds in being intimate with Sans a barrier impossible to break, he wants so badly to be able to express him how deep his love and his desire is. But he is so afraid of failing him again. Of being _vulnerable_. Of being _weak_. Of being utter and filthy trash.

But Sans is not deterred by his fears. He wants to show him how beautiful he is on his eyes. And concludes the only way he could do this is if Red closes his eyes. If he give up control.

So Sans asks and Red agrees to try.

“think of a safe word red, something that holds a meaning to you, for me to stop no matter what are we doing, that way i'll know what is happening, that way i could help you get out of it and stay here, with me”

And he thinks... then he chooses

“Firefly”

Sans is fastening the blindfold around his skull, over his sockets.

“it's a nice word”

Red like those little bugs. It reminds him how truly amazing the surface is. How incredible the way nature makes beauty.

Carefully Sans began to undress him. The world is dark, but Sans is right here. He could feel him.

“I-if I do something weird... tell me, okay?”

He is nervous and tense as Sans lay him to the bed.

“shh... don't talk” Sans voice is soothing and _commanding_ “just feel, and hear”

He does just that. Pleasantly surprised how much he likes hearing Sans order him. He could feel Sans breath on his sternum. Caressing a large terrible crack in the middle. Then he kissed it. And he caress and kiss all the small cracks that mark his entire body. With such tender, such care, Red is crying now feeling kindness and care on each gesture.

“i love you, red” Sans low voice tells him “i love every single one of those wounds, because they tell me your story, the story of how truly strong you really are. How many hardships you survived. How brave you are by being here and still have the fortitude to smile and love”

Red is now an ugly sobbing mess. But Sans doesn't seem to care.

“your past is not who you are, you are amazing and good, red. maybe you struggle to see that but i intend to show you the monster you really are, not who he told you. i know you _deserve_ all the love in the world”

And with that Sans kisses him. And red kisses back, trying desperately to pour in that kiss all his love, all his need to find an anchor, someone who need him, someone who loves him.

“he doesn't have power over you anymore, he doesn't own you”

Sans hands are all over his body, seemingly every where, rubbing his ribs, his knee on the middle of his legs, moving slowly but providing a delicious friction that he melts to.

When a moan escapes his mouth Sans devours it with thirst, his hands placed on his skull holding it careful. Their entire bodies pressed together, and it's not wrong. It's not filthy...

Sans works every single part of his body, till he is trembling and moaning mess, really close to completion. Sans hand is gently rubbing his sacrum, but Red wants more. He is calling desperately Sans name. Completely lost in pleasure. He is closer and closer to the edge.

“kiss me” Sans commands

And he does, Reds seek out desperately for Sans face and is guided gently to the other's body. He holds onto Sans like a life line. Sans voice is absolute.

Is safety. Is home.

Sans wrap his body with his own. His legs around his his arms around his shoulder blades.

“cum” is the final order.

And Red does and screams for Sans. Calling him. Ecstasy exploding in white and small color little stars fill him. Magic spilling, bursting in completion.

“I love you” his voice is shaking with the force that just hit him.

“i love you, red”

He feel safe on the hands of Sans, and he noticed he loved him much more deeply than he could ever believed possible. He put his trust on sans. Sans is worth fighting against what is inside of him. Sans isn't going to leave him alone.

 

**Author's Note:**

> Surprise! 
> 
> And Happy B-day ChocoboFangirl! Hope you are having a great day. I really hope you like your present. =) Sending you lots of hugs, and many blessings on this special day!


End file.
